Electromagnet



May 13, 1930.

E. R. CARICHOFF ELEGTROMAGNET Vf fl ...N/ n r ...Im lm 1. if tC A n. QOH hm V l.. D@

. Eugen Patented May 1 3, 1930 UNITED STATES PATENT OFFICE EUGENE It. CARIGHOFF, OF SCHENECTADY, NEW YORK, ASSIGNOR TO GEN EMI ELEG- TRIC COMPANY, A CORPORATION OFNEW YORK ELECTROMAGNET Application led December 1, 1927. Serial No. 237,075.

My present invention relates to electromagnets, particularly for operating circuit controlling devices, and the invention comprises various new and useful improvements in the magneticstructure and the windings therefor, as well as in the mounting arrangement el both the stationary and movable parts of the operating electromiagnet:

Among the principal objects of the invention are to increase the power, efficiency and quietness el the operating electro-magnet, particularly alternating current service, and to improve the construction of the operating electro-magnet so as to render both manufacture and maintenance of. the same in service relatively simple and inexpensive.

rllhe operating electromagnet embodying the several improvements of the present in vention is particularly advantageous when applied to an alternating current contacter such as illustrated in the accompanying drawing, although various features of the invention may be utilized separately in other forms or" .operating electromagnets or other devices with equal advantage whenever deln the drawing, Fig. l, is a front view of a three pole alternating current contacter having an operating electromagnetembodying the improvements of the present invention 1n their preterred forni. Fig.. 2 is a sectional. view ol the contactor shown in Fig. l along the lines 2-#2 and reveals the details of' construction el the operating electro-magnet. Fig. il is an enlarged perspective view ,0l one of the poles oil the contacter operating electro-magnet showing more clearly the construction ci the pole shading Winding used 1n alternating current service. Fig. Ll is a sectional view ci the rotatable shaft which carries the movable switch members and the movable magnetic member of' the eleotromagnet. And Fig. 5 is a side view showing the detailed construction of the contact lingers and the magnetic blowout provided Ifor each pole of the contacter. with certain parts brolren away in order to more clearly illustrate the details of construction.

The contacter shown in Fig. l comprises the movable switch members l0, ll and l2 which are mounted upon the rotatable shaft 13 to form a. three pole switch particularly adapt* ed for alternating current service. The pivotal supports 14 and l5 for the contactor shaft 13 together with the magnetic blowouts i6, i7 and 18 for the movable contacts l0, ll and l2 and also the operating electro-magnet 19 all are mounted upon the base 20. Base 20 is preferably formed of suitable insulating man terial. The several novel features of the switch mechanism itself are described and claimed in my divisional application Serial No. clans, and October rr, i929.

The operating electro-magnet 19 is designed to be energized with alternating cur rent. As is more clearly shown in Fig. 2 the operating electro-magnet has a stationary frame 21 and a movable armature 22, each ol which is E shaped. The energizing windings 23 of the electro-magnet are located on a spool 2li preferably formed of molded insulating' material such as balrelite and the like. The spool 24 is formed to be seated upon the middle leg of the E shaped frame 2l and is provided with a bell shaped space within the Winding 23 for receiving the cooperating middle leg of the E shaped armature 22. The stationary core 2l is secured to the base 20 by means of the blocks 26 which have lugs projecting into slots 27 formed in the stationary core. Thus by tightening the bolts 28 the stationary core 2l isclamped firmly in engagement with base 20 without the necessity of passing fastening bolts through the laminated core structure itself.

The slot 27 in the core 2l is shown more fully in Fig. 3. This figure also shows the pole shading winding 32 which is located upon each of the outside legs of the E shaped frame 2l. As shown in Fig. 3 the pole shading winding 32 is in the torni of a closed loop of current conducting material, preferably brass. One side of the loop is located in the slot 33 formed in the pole face of the core. The pole shading winding 32, preferably is loosely mounted on the core 2l and is held in position by means of lugs or fingers 34'extending from the side of the pole shading winding loop into the center of the hollow rivet 35 which maintains the lamination of this pole shader arrangement is the loose mounting which prevents injury to the pole shading Winding due to the shocks' and jars inherently accompanying the operation of the armature 22 into the engagement with frame 21. Moreover it is a relatively simple matter to remove and replace the pole shading Winding whenever necessary.

The armature 22 of the electro-magnet is mounted upon the arm 25 which is removably secured to the shaft 13 by means of the bolts 36. In order to provide mounting for the armature 22 that will permit pivotal and twisting movement thereof so as to insure proper alinement of the armature with the frame the armature 22 is loosely mounted upon a bar 37 which extends through the slot 38 formed in the armature 22. The bar 37 is provided with a centrally located hump 33 to permit more readily the tilting and twisting movement of the armature 22. The bar 37 is removably secured to the arm 25 by means of the bolts 40 with the back of the armature 22 extending through the opening 41 provided in the arm 25. In order to relieve the bar 37 of the weight of the armature 22, an additional bar 42 may be provided at the bottom of the opening in the arm 25.

The arm 25 is mounted upon the shaft 13 by means of a spacing plug 43. It will be observed from Fig. 4 that the shaft 13 .is formed of molded insulating material 1n truss shape. The spacing plug 43 is arranged to fit snugly into one of the end pockets of shaft 13 and provided with suitable holes through which the holding bolts 36 previously referred to are passed. An additional bolt 44 is provided for more firmly securing the plug 43 to the shaft 13 and at the saine time fastening the auxiliary switch mechanism 45 to the shaft.

It will be noted in Fig. 4 that the contactor shaft 13 is provided with shoulders at each end with a central opening formed therein to receive the pivotal bearing pins 46 which are secured to the supports 14 preferably by riveting thereto. With the switch shaft 1,3 formed of molded insulating material this bearing construction requires no oil and. will withstand long service without appreciable wear. l

The movement of the armature 22 away from the core 21 is limited by the stop 47 which is secured at one end by the bolt 28 and preferably is provided with a buffer 48 of a Wear resisting and resilient material such as fibre. The stop 47 also carries the clamp 50 which serves to hold the winding spool 24 securely seated upon the middle leg of the core 2l. With this construction the removal of the stop 47 by loosening the bolt 28 readily permits the operating winding 23 to be removed for repair.

The construction' of the contact 'ngers and of the magnetic blowout provided for each pole of the contactor is shown in Fig. 5. In this figure the movable contact finger 51 is carried upon an arm 52 which is removably secured to the shaft 13 by the bolt 53. Preferably shallow channels as indicated by the dotted lines 154 in Fig. 4 are provided on the back side of the shaft 13 for receiving the arms 52. In this way the single bolt 53serves to hold the arm 52 in proper alignment on the shaft 13. vThe finger 51 has a slot for receiving the guide 55 which is fiXedly secured to the free end of arm 52 so as to project at right angles thereto. The arm 52 also is provided with a pointed pivot pin 56 which fits into a corresponding notch or depression in the contact 51 so as to form a pivotal bearing for the latter. The end of the guide 55 is formed in T shape and the compression spring 57 is of sufficient diameter to pass freely over the laterally extending tongues at the end of the guide into engagement with the Contact finger 51. To maintain the spring 57 under compression, the cup shaped washer 58 is arranged to seat the outer end of the spring 57. As shown in Fig. 1 the washer 58 is provided With an elongated slot which permits the T end of the guide 55 to pass therethrough. Thereupon the washer 58 is given a half turn to bring the slot out of alinement with the T head of the guide 55. Preferably holding lugs 59 are punched up from the edges of the slot in the washer 58 so as to prevent accidental return of the slot in the washer into alinement with the T head of the guide 55. This arrangement permits ready removal of the compression spring 15 as well as the contact 51 from the guide 55 in case the contact 51 should become worn or damaged in the service. The contact 51 is connected to the stationary terminal 59 by means of the flexible shunt or connector 60.

The stationary contact 61 which cooperates with the Contact finger 51 in closing and opening the circuit controlled by the contactor is removably mounted upon the support 62 which is secured to the base 2O by the bolt 63. The support 62 also is rigidly connected to one end of the blowout coil 64. The other end of the blowout coil is connected to the terminal 65 from which the line conductor 66 extends. It will be observed that support 62 is substantially of C shape. The support 62 is of sufficient width as shown in Fig. 1 to almost completely surround the blowout coil 64. The upper end of the C shaped support 62 is provided with an upturned finger 67. The arc chute 68 is arranged to be secured in position by means of the upturned finger 67 and the curved portion of the support 62. As shown in Fig. l the arc chute 68 is formed of spaced apart walls of good insulating material. Suitable spacing lugs 69 and 70 are interposed between the walls forming the arc chute and CII the bolts which hold the walls together pass through these lugs. The interior surfaces of the walls forming the are chute are each provided with a curved shoulder 7l adjacent the lug 69. The relation of the lug 69 and the curved shoulder 71 are such that the arc chute fits snugly upon the curved portion of the support 62 with the upturned finger 67 thereon engaging with the lugs 69 and extendine' between the side walls of the arc chute. In this Way the arc chute 68 is iirmly maintained in its proper position to receive any are which may occur upon the separation of the contact 5l from the contact 6l. The support 62 also serves as an arc horn extending entirely along one edge of the arc chute. f

The blowout flux set up by the coil 64 is conducted in the region of the are by means of the laminated magnetic pole pieces 7l which extend from the magnetic core passing through the blowout coil 64. As shown in Figure l the laminated pole pieces 7l' extend on either side of the arc chute 68 adjacent to the point of operation of the contacts scribed win be evident that the are chute may be readity lifted out of engagement with,

the support 652, as indicated in Fig. l thereby exposing the contact fingers 5l and the contact 6l iter inspection and any necessary repairs..

The operation of the electromagnetic switch just described will be apparent.. Upon energizatiou oi the operating windings 23 the movable armature Q2 is attracted into engagement with the frame 2l. The relative length oi' the legs of the armature and core are so proportioned that only the outer legs are carried into abutting engagement. This leaves a slight air gap between the centre legs of the core and the armature. Aiso the loose mounting oi the armature 22 upon the arm 25 the armature permits freedom of adjustment into intimate contact with the core 2l irrespective oi any slight misalinement that may exist therebetween. This method of mounting the armature 22 together 'with the arrangement of the pole shading Winding 32 results in very quiet operating of the electromagnet when energized with `alternating current.

Upon de-energization or" the operating winding 23 the ont of balance Weight oi the armature and the linger springs insure a quiclr opening of the switch. The blowout coils and arc chutes associated therewith in- .tacts What l claim as new and desire to secure by Letters Patent of the United States is 1. An electromagnetic device comprising a base, an'electrolnagnet having a frame pro. vided with slots thereinand provided with a winding, clamping lingers secured to the base and engaging said slots to hold the frame in position, and an armature therefor cooperating with said frame and loosely mounted so as to be free to adjust itself in proper alignment with the frame.

2. rlhe combination with .an alternatin current electromagnet having a laminate ma notie frame of substantially E shape, sai frame having slots transverse the laminan tions oppositely disposed in the outer legs thereof, a supporting base for the frame, clamping members having lingers for engaging said slots, and means for removably securing the clamping members with the frame clam ed therebetween to said base.

3. n an alternating current electromagnet, the combination of a laminated magnetic structure having a slot formed in the pole face thereof to divide the pole face into two areas, a pole shading Windingl in the orm of a loop substantially larger than one of said areas, and means for loosely supporting said poleshading winding to surround said one area with one portion oi the loop movable in said slot.

4. In an alternating current electromagnet,

i with said magnetic structure for loosely maintaining the pole shading'winding in operating relation therewith.

5. ln an alternating current electromagnet, the combination of a laminated magnetic structure having a slot formed transverse the laminations in a pole face thereof, ahollow rivet extending through the frame laminations adjacent' said pole face for maint ing the same together, a loop-sha shading winding having one si the loop disposed in said slot and provided r i extensions rom each end of the loop adapted to engage with the ends of said rivet for loosely maintaining the pole shading winding in operating position. l

6. An' electromagnet having a movable magnetic member provided with a non-circular opening therein, and means for removably supporting said magnetic member including a non-circular supporting member loosely disposed in said openingto freely permit relative movement between the supporting means and the movable magnetic member.

7. An electromagnet having a mov able electromagnetic member provided with a noncircular opening therethrough, a pivoted supn portingl arm -for the magnetic member, and

means for loosely mounting the magnetic member on the support including a non-circular member loosely passing through said opening in the magnetic member and secured to said supporting arm.

8. An electromagnet having a movable electromagnetic member provided with a noncircular opening therein, a pivotally mounted arm having spaced-apart portions for receiving the magnetic member loosely therebetween, and a non-circular support loosely extending through said opening in the magnetic member and secured at each end to said spaced-apart portions whereby limited relative movement of the armature with respect to the support in all directions is secured.

9. An alternating current electromagnet having a movable laminated magnetic member of substantially E shape and provided with a non-circular o ening transverse the laminations opposite tlie middle leg thereof, a pivoted shaft having an arm extending therefrom with portions disposed on either side of the magnetic member for supporting the same, and a bar extending between said portions through said opening in the magnetic member for loosely supporting the same to permit relative movement thereof with respect to the arm in all directions.

10. An electromagnet having relatively movable magnetic members, a magnetizing winding having a spool with a core formed therein arranged to closely surround one of said members with the end of said member intermediate the ends of the spool and providing a core space of increased area for receiving the other relatively movable member therein.

11. An electromagnet comprising a magnetizing. winding having a spool provided with a core space of different area at the opposite ends thereof, a magnetic member ar ranged to substantially ll said core space with the end of said member intermediate the ends oit the spool, and second magnetic member freely operable Within the remaining -eore space oi' the spool into engagement with said rst member.

l2. An electromagnet comprising a netizing Winding having a spool provided with bell-shaped core space, a magnetic member, and cooperating relatively movable magnetic members one disposed in said core space with the end of the member extending intermediate the ends of the core space and another magnetic member freely operable into engagement therewith.

13. An electromagnet comprising a magnetic member; a magnetiaing Winding having a spool disposed on said magnetic member with the end of the member intermediate the ends ofthe spool, said spool providing a bellshaped core space extending from the end of said magnetic member, and a pivotally mounted magnetic member operable in said bell-shaped core space vinto engagement with said first magnetic member.

14. An electromagnet comprising an E- shaped magnetic frame, a magnetizing winding having a spool providing a bell-shaped core space for mounting the winding upon the middle leg of said structure with the end of said middle leg intermediate the ends of the core space, and a cooperatin movable mag-l netic member of substantial y E shape pivotally mounted for movement into aligned attracted relation with said E-shaped frame with the lniddle leg of the movable magnetic member operable in said bell-shaped core space.

In witness whereof, I have hereunto set my hand this 30th day of November, 1927.

EUGENE R. CARICHOFF. 

